Liquid-crystal polymer, laminated material, liquid-crystal polymer solution, and method of forming liquid-crystal polymer film

ABSTRACT

A liquid-crystal polymer includes at least one repeating unit having a spiro structure, and the repeating unit occupies 1 mol % to 20 mol % of the liquid-crystal polymer. The liquid-crystal polymer is composed of the following repeating units: 1 mol % to 20 mol % of 
                         
10 mol % to 35 mol % of
 
                         
10 mol % to 35 mol % of
 
                         
10 mol % to
 
50 mol % of
 
                         
and 10 mol % to 40 mol % of
 
                         
AR 1  is
 
                         
wherein each of ring R and ring S is independently a C 3-20  ring, ring R and ring S share a carbon atom, and each of K 1  and K 2  is independently a C 5-20  conjugated system. Each of AR 2 , AR 3 , AR 4 , and AR 5  is independently AR 6  or AR 6 —Z—AR 7 .

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/869,669 filed on Jul. 2, 2019, the entirety of which is incorporatedby reference herein.

TECHNICAL FIELD

The technical field relates to liquid-crystal polymer.

BACKGROUND

In recent years, liquid-crystal polymer (LCP) has been widely utilizedin many high-value, high-end applications, especially in LCP films. SuchLCP films have low moisture absorption, low dielectric constant, and lowdielectric loss. Moreover, the polyimide (PI) films utilized in flexiblecopper clad laminate (FCCL) in mobile cell phones cannot satisfy theneeds of 4G/5G high speed communication, and the PI films may possiblybe replaced with LCP films. However, traditional LCP materials have ahigh-order molecular alignment, which can easily result in acrystallinity difference between MD and TD directions during theprocesses of film extrusion and film blowing. As such, the LCP filmstrength in the MD orientation is high, and the LCP film can easilycrack in the TD direction. Accordingly, the thermal processes forpreparing LCP films need high-threshold equipments and technologies.

Accordingly, a novel soluble LCP composition is called for, in order forsolution-type and film-level LCP to be applied in FCCL product.

SUMMARY

One embodiment of the disclosure provides a liquid-crystal polymer,including at least one repeating unit having a spiro structure, and theliquid-crystal polymer includes 1 mol % to 20 mol % of the repeatingunit.

One embodiment of the disclosure provides a laminated material,including a support; and a liquid-crystal polymer film disposed on thesupport, wherein the liquid-crystal polymer film includes the describedliquid-crystal polymer.

One embodiment of the disclosure provides a liquid-crystal polymersolution, including 100 parts by weight of solvent; and 0.01 to 100parts by weight of the described liquid-crystal polymer.

One embodiment of the disclosure provides a method of formingliquid-crystal polymer film, including coating the describedliquid-crystal polymer solution onto a support; and removing the solventto form a liquid-crystal polymer film on the support.

A detailed description is given in the following embodiments.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that one or more embodiments may be practiced without thesespecific details.

One embodiment of the disclosure provides a liquid-crystal polymerincluding at least one repeating unit having a spiro structure, and theliquid-crystal polymer includes 1 mol % to 20 mol % of the repeatingunit. For example, the liquid-crystal polymer is composed of thefollowing repeating units: 1 mol % to 20 mol % of

10 mol % to 35 mol % of

10 mol % to 35 mol % of

10 mol % to 50 mol % of

and 10 mol % to 40 mol % of

wherein AR¹ is

each of ring R and ring S is independently a C₃₋₂₀ ring, ring R and ringS share a carbon atom, and each of K¹ and K² is independently a C₅₋₂₀conjugated system; wherein each of AR², AR³, AR⁴, and AR⁵ isindependently AR⁶ or AR⁶—Z—AR⁷, each of AR⁶ and AR⁷ is independently

or a combination thereof, and Z is —O—,

or C₁₋₅ alkylene group; wherein each of X and Y is independently H, C₁₋₅alkyl group, CF₃, or

wherein R¹ is H, CH₃, CH(CH₃)₂, C(CH₃)₃, CF₃, OCH₃, or

and n=1 to 4.

In some embodiments, the liquid-crystal polymer is composed of thefollowing repeating units: 1 mol % to 20 mol % of

10 mol % to 35 mol % of

10 mol % to 35 mol % of

and 10 mol % to 50 mol % of

Each of AR¹, AR², AR³, and AR⁴ is defined as above, and the relateddescription is not repeated here.

In some embodiments,

can be reacted to form the liquid-crystal polymer.

(sum of diol) and

(diacid) have a molar ratio of 1:1. If

(sum of diol) and

(diacid) have a molar ratio of greater than or less than 1, excessive

or excess

cannot be reacted to copolymerize.

In some embodiments, the repeating unit

or a combination thereof. The repeating unit

or a combination thereof In some embodiments, the repeating unit

In some embodiments, the repeating unit

or a combination thereof In some embodiments, the repeating unit

In the liquid crystal polymer, if the content of

such as

is too low, the solubility enhancement of the liquid-crystal polymerwill be limited. If the content of

such as

is too high, the crystallinity of the liquid-crystal polymer will belowered, and the melting point of the liquid crystal polymer willdisappear. In the liquid-crystal polymer, if the content of

such as

is too low, the crystallinity of the liquid-crystal polymer will bedegraded. If the content of

such

is too low, the solubility of the liquid-crystal polymer will bedegraded. If the content of

such as

is too high, the solubility of the liquid-crystal polymer will bedegraded. If the content of

such

is too high, the crystallinity of the liquid-crystal polymer will bedegraded. If the content of

such as

is too low, the solubility of the liquid-crystal polymer will belowered. If the content of

such as

is too high, the crystallinity of the liquid-crystal polymer will bedegraded. If the content of

such as

is too low, the crystallinity of the liquid-crystal polymer will bedegraded. If the content of

such as

is too high, the solubility of the liquid-crystal polymer will bedegraded. If the content of

such as

is too low, the solubility of the liquid-crystal polymer will bedegraded. If the content of

such as

is too high, the dielectric property of the liquid-crystal polymer willbe degraded, the crystallinity of the liquid-crystal polymer will bedegraded, or the liquid-crystal polymer cannot be successfullypolymerized.

In some embodiments, the liquid-crystal polymer is composed of thefollowing repeating units: 1 mol % to 15 mol % of

15 mol % to 35 mol % of

15 mol % to 35 mol % of

15 mol % to 35 mol % of

and 10 mol % to 40 mol % of

Each of AR¹AR², AR³, AR⁴, and AR⁵ is defined as above, and the relateddescription is not repeated here.

In some embodiments, the liquid-crystal polymer has an inherentviscosity of 0.1 dL/g to 5 dL/g. If the inherent viscosity of theliquid-crystal polymer is too low, the film formability of theliquid-crystal polymer will be degraded. If the inherent viscosity ofthe liquid-crystal polymer is too high, the solubility of theliquid-crystal polymer will be degraded.

The method of manufacturing the liquid-crystal polymer of the disclosureis not specifically limited. For example, the hydroxyl-containingmonomer or amine-containing monomer is firstly reacted with excessamount of fatty acid anhydride to perform acylation to form an acylatedcompound. The acylated compound is reacted with carboxylicacid-containing monomer to perform transesterification to form theliquid-crystal polymer. Alternatively, the acylated compound that ispre-acylated can be reacted with the carboxylic acid-containing monomerto perform the transesterification to form the liquid-crystal polymer.

The fatty acid anhydride content in the acylation can be 1.0 to 1.2times the total equivalent of the hydroxyl group and amine group. Theacylation can be performed at 130° C. to 180° C. for 5 minutes to 10hours, such as 140° C. to 160° C. for 10 minutes to 3 hours.

The fatty acid anhydride for the acylation in the disclosure is notspecifically limited and may include acetic anhydride, propionicanhydride, butanoic anhydride, isobutanoic anhydride, pentanoic acid,trimethylacetic anhydride, 2-ethylhexanoic anhydride, monochloroaceticanhydride, dichloroacetic anhydride, trichloroacetic anhydride,monobromoacetic anhydride, dibromoacetic anhydride, tribromoaceticanhydride, monofluoroacetic anhydride, difluoroacetic anhydride,trifluoroacetic anhydride, glutaric anhydride, maleic anhydride,succinic anhydride, β-bromopropionic anhydride, the like, or acombination thereof. In some embodiments, the fatty acid anhydride canbe acetic anhydride, propionic anhydride, butanoic anhydride, orisobutanoic anhydride.

A catalyst can be added into the acylation and the transesterification.The catalyst can be a known catalyst for polymerization of polyester,such as metal salt catalyst (e.g. magnesium acetate, tin acetate,tetrabutyl titanate, lead acetate, potassium acetate, antimony trioxide,or the like), or organic catalyst such as heterocyclic compound havingat least two nitrogen atoms (e.g. N, N′-dimethylaminopyridine,N-methylimidazole, pyrazole, or the like).

An additive can be added into the acylation reaction and thetransesterification reaction, and the specific additive those are knownin the art includes binding agent, anti-precipitation agent, UVabsorber, thermal stabilizer, anti-oxidant, or a combination thereof.

The aromatic liquid-crystal polymer can be manufactured by batch-typeequipment, continuous-type equipment, or the like.

The liquid-crystal polymer can be dissolved in a solvent to form aliquid-crystal polymer solution. The solvent and the liquid-crystalpolymer may have a weight ratio of 100:0.01 to 100:100. For example, theliquid-crystal polymer solution may contain 100 parts by weight of thesolvent and 0.01 to 100 parts by weight of the liquid-crystal polymer.In one embodiment, the crystal liquid solution contains 100 parts byweight of the solvent and 1 to 40 parts by weight of the liquid-crystalpolymer. Alternatively, the liquid-crystal polymer solution contains 100parts by weight of the solvent and 1 to 20 parts by weight of theliquid-crystal polymer. If the amount of the liquid-crystal polymer istoo low, the coated film cannot easily achieve the desired thickness. Ifthe amount of the liquid-crystal polymer is too high, the solutionviscosity will be too high to be coated. The liquid-crystal polymer issimilar to that described above, and the related description is notrepeated here. For example, the solvent can be halogen-containingsolvent (such as 1-chlorobutane, chlorobenzene, 1,1-dichloroethane,chloroform, or 1,1,2,2-tetrachloroethane), ether solvent (such asdiethyl ether, tetrahydrofuran, or 1,4-dioxolane), ketone solvent (suchas acetone or cyclohexanone), ester solvent (such as ethyl acetate),lactone solvent (such as butyl acrylate), carbonate solvent (such asvinyl carbonate or acrylic carbonate), amine solvent (such astriethylamine or pyridine), nitrile solvent (such as acetonitrile),amide solvent (such as N,N′-dimethylformamide, N,N′-dimethylacetamide,tetramethylurea, or N-methylpyrrolidone), nitro solvent (such asnitromethane or nitrobenzene), sulfide solvent (such as dimethylsulfoxide or butane disulfone), phosphide solvent (hexamethyl phosphorictriamide or tri-n-butyl phosphide), paraffin, olefin, alcohol, aldehyde,aromatic hydrocarbon, terpene, hydrogenated hydrocarbon, heterocycliccompound, or a combination thereof.

The liquid-crystal polymer solution may further include another resin.For example, at least one resin that is not the liquid-crystal polymercan be added to the liquid-state composition. The resin may includethermoplastic resin or thermosetting resin. The thermoplastic resin canbe polypropylene, polyamide, polyester (such as non-liquid-crystalpolyallylate), polyphenylene sulfide, polyetherketone, polycarbonate,polyether sulfone, polyphenylene ether, polyetherimide, fluororesin, anelastomer (typically, copolymer of glycidyl methacrylate andpolyethylene), or a modified product thereof. The thermosetting resincan be novolac resin, epoxy resin, polyimide resin, or cyanate resin. Inaddition, the other resin can be dissolved in the solvent for theliquid-crystal polymer when the other resin is adopted.

In addition, the liquid-crystal polymer solution may further includeanother additive to enhance the size stability, mechanical properties,thermal conductivity, dielectric properties, thermal stability, lightstability, anti-aging properties, coatability, and film formability. Theadditive may include inorganic filler (e.g. silica, alumina, titania,zirconia, hydrous aluminum silicate, calcium carbonate, calciumphosphate, barium titanate, strontium titanate, or aluminum hydroxide),organic filler (e.g. epoxy resin powder, melamine resin powder, polyurearesin powder, benzomelamine formaldehyde resin powder, styrene resinpowder, fluororesin powder, or fluororesin dispersion), anti-oxidant,thermal stabilizer, UV absorber, light stabilizer, anti-aging agent,toughening agent, chain extender, plasticizer, crosslinking agent,additives for coating inks (e.g. defoamer, leveling agent, wetting anddispersing agent, thickener, thixotropy controller, adhesion promoter,or coupling agent), or a combination thereof.

The liquid-crystal polymer film can be prepared by the following method.First, the described liquid-crystal polymer solution is coated onto asupport to make the coated layer flat and uniform. The coating methodcan be any suitable method such as roll coating, dip coating, spraycoating, spin-on coating, curtain coating, slot coating, or screencoating. The support can be copper foil, glass, aluminum foil, oranother suitable support. After coating the liquid-crystal polymersolution, the solvent is removed to form the liquid-crystal polymer filmon the support. The support can be then optionally removed (depending onthe application requirement) by the method such as etching or peeling.

The method of removing the solvent is not specifically limited, whichcan be evaporation. The solvent can be evaporated by heating, reducingpressure, ventilation, or the like. In the above methods, the heatingevaporation is beneficial in high yield and easy to operate. On theother hand, the coating can be heated in ventilation to evaporate thesolvent. For example, the coating can be pre-heated in ventilationdrying at 60° C. to 200° C. for about 10 minutes to 2 hours, and thenheated in ventilation at 200° C. to 400° C. for about 30 minutes to 10hours.

The thickness of the liquid-crystal polymer film prepared by the abovemethod is not limited, which can be 1 micrometer to 100 micrometers.

One embodiment of the disclosure provides a laminated material,including the support and the liquid-crystal polymer film on thesupport. The support can be copper foil, glass, aluminum foil, oranother suitable support. In some embodiments, the laminated materialincludes the copper foil and the liquid-crystal polymer film on thecopper foil. An adhesive layer can be further disposed between thesupport (e.g. copper foil) and the liquid-crystal polymer film toenhance the adhesion between the support (e.g. copper foil) and theliquid-crystal polymer film. When the laminated material is applied tothe printed circuit board, some adhesive having excellent electricproperties (e.g. fluororesin) can be introduced to reduce thetransmission loss of the printed circuit board. The laminated materialcan be further manufactured as a laminated material with double-sidedcopper foils. For example, the laminated materials with single-sidedcopper foil can be attached to each other and heat pressed to form thelaminated material with double-sided copper foils, in which a middlelayer of the liquid-crystal polymer film is interposed between a toplayer of the copper foil and a bottom layer of the copper foil.

An appropriate content ratio of

is introduced into the liquid-crystal polymer to combine withappropriate content ratios of

to efficiently enhance the solubility of the liquid-crystal polymer.

Below, exemplary embodiments will be described in detail so as to beeasily realized by a person having ordinary knowledge in the art. Theinventive concept may be embodied in various forms without being limitedto the exemplary embodiments set forth herein. Descriptions ofwell-known parts are omitted for clarity.

EXAMPLES Example 1

130.2 g of 4,4′-biphenol (0.7 mole), 116.2 g of isophthalic acid (0.7mole), 131.6 g of 6-hydroxy-2-naphthalene carboxylic acid (0.7 mole),95.9 g of 4-aminobenzoic acid (0.7 mole), and 286 g of acetic anhydride(2.8 mole) were mixed, then heated to 150° C. to be reacted at 150° C.for 3 hours under nitrogen, and then heated to 320° C. to be reacted at320° C. for 1 hour. Thereafter, the temperature was kept at 320° C. andthe pressure was gradually vacuumed until the reaction achieved idealviscosity. The vacuum was then broken by using of nitrogen, and theproduct was extruded out by the nitrogen pressure. The product had aninherent viscosity of 0.81 dL/g, which was measured with an Ostwaldviscometer. The product was completely dissolved inN-methyl-2-pyrrolidone (NMP) at 140° C. to obtain a solution with aconcentration of 0.3 g/dL. The inherent viscosity of the solution atroom temperature (25° C.) was measured by the Ostwald viscometer. Theproduct had thermal decomposition temperature (Td) of 453° C. (measuredby thermogravimetric analysis, TGA). The product had melting point (Tm)of 286° C. and glass transition temperature (Tg) of 169° C., which weremeasured by differential scanning calorimetry (DSC). The product wasdissolved in NMP to form a solution with a solid content of 8 wt %(maximum solubility). The solution was coated onto a copper foil anddried, and then heat treated at 200° C. to 300° C. to obtain aliquid-crystal polymer film (with a thickness of 25 micrometers)attached to the copper foil. The copper foil was then removed by etchantto obtain the liquid-crystal polymer film alone. In the above reaction,the chemical structure of 4,4′-biphenol is

the chemical structure of isophthalic acid is

the chemical structure of 6-hydroxy-2-naphthalene carboxylic acid is

and the chemical structure of 4-aminobenzoic acid is

Example 2

86.3 g of spirobiphenol (0.28 mole), 78.2 g of 4,4′-biphenol (0.42mole), 116.2 g of isophthalic acid (0.7 mole), 131.6 g of6-hydroxy-2-naphthalene carboxylic acid (0.7 mole), 95.9 g of4-aminobenzoic acid (0.7 mole), and 286 g of acetic anhydride (2.8 mole)were mixed, then heated to 150° C. to be reacted at 150° C. for 3 hoursunder nitrogen, and then heated to 320° C. to be reacted at 320° C. for1 hour. Thereafter, the temperature was kept at 320° C. and the pressurewas gradually vacuumed until the reaction achieved ideal viscosity. Thevacuum was then broken by nitrogen, and the product was extruded out bythe nitrogen pressure. The product had an inherent viscosity of 0.71dL/g, which was measured with an Ostwald viscometer. The product wascompletely dissolved in NMP at 140° C. to obtain a solution with aconcentration of 0.3 g/dL. The inherent viscosity of the solution atroom temperature (25° C.) was measured by the Ostwald viscometer. Theproduct had Td of 450° C. (measured by TGA). The product had Tm of 243°C. and Tg of 165° C., which were measured by DSC. The product wasdissolved in NMP to form a solution with a solid content of 16 wt %(maximum solubility). The solution was coated onto a copper foil anddried, and then heat treated at 200° C. to 300° C. to obtain aliquid-crystal polymer film (with a thickness of 40 micrometers)attached to the copper foil. The copper foil was then removed by etchantto obtain the liquid-crystal polymer film alone.

In the above reaction, the chemical structure of spirobiphenol is

Example 3

215.6 g of spirobiphenol (0.7 mole), 116.2 g of isophthalic acid (0.7mole), 131.6 g of 6-hydroxy-2-naphthalene carboxylic acid (0.7 mole),95.9 g of 4-aminobenzoic acid (0.7 mole), and 286 g of acetic anhydride(2.8 mole) were mixed, then heated to 150° C. to be reacted at 150° C.for 3 hours under nitrogen, and then heated to 320° C. to be reacted at320° C. for 1 hour. Thereafter, the temperature was kept at 320° C. andthe pressure was gradually vacuumed until the reaction achieved idealviscosity. The vacuum was then broken by nitrogen, and the product wasextruded out by the nitrogen pressure. The product had an inherentviscosity of 0.2 dL/g, which was measured with an Ostwald viscometer.The product was completely dissolved in NMP at 140° C. to obtain asolution with a concentration of 0.3 g/dL. The inherent viscosity of thesolution at room temperature (25° C.) was measured by the Ostwaldviscometer. The product had Td of 413° C. (measured by TGA). The producthad no Tm and Tg of 231° C., which were measured by DSC. The product wasdissolved in NMP to form a solution with a solid content of 8 wt %(maximum solubility).

As shown in the comparison of Examples 1 and 2, appropriate amount ofthe spirobiphenol could efficiently increase the solubility of theliquid-crystal polymer, thereby increasing the thickness of theliquid-crystal polymer film. As shown in the comparison of Examples 2and 3, an overly high ratio of the spirobiphenol resulted in theliquid-crystal polymer without melting point, and reduced thecrystallinity of the liquid-crystal polymer.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the disclosed methods andmaterials. It is intended that the specification and examples beconsidered as exemplary only, with the true scope of the disclosurebeing indicated by the following claims and their equivalents.

What is claimed is:
 1. A liquid-crystal polymer, being composed of thefollowing repeating units: 1 mol % to 20 mol % of

10 mol % to 35 mol % of

10 mol % to 35 mol % of

10 mol % to 50 mol % of

and 10 mol % to 40 mol % of

wherein AR¹ is

wherein each of ring R and ring S is independently a C₃₋₂₀ ring, ring Rand ring S share a carbon atom, and each of K¹ and K² is independently aC₅₋₂₀ conjugated system, each of AR², AR³, AR⁴, and AR⁵ is independentlyAR⁶ or AR⁶—Z—AR⁷, each of AR⁶ and AR⁷ is independently

or a combination thereof, and Z is —O—,

or C₁₋₅ alkylene group; wherein each of X and Y is independently H, C₁₋₅alkyl group, CF₃, or

wherein R¹ is H, CH₃, CH(CH₃)₂, C(CH₃)₃, CF₃, OCH₃ , or

and n=1 to
 4. 2. The liquid-crystal polymer as clamed in claim 1,wherein

or a combination thereof.
 3. The liquid-crystal polymer as claimed inclaim 1, wherein

or a combination thereof.
 4. The liquid-crystal polymer as claimed inclaim 1, wherein


5. The liquid-crystal polymer as claimed in claim 1, wherein

or a combination thereof.
 6. The liquid-crystal polymer as claimed inclaim 1, wherein


7. The liquid-crystal polymer as claimed in claim 1, having an inherentviscosity of 0.1 dL/g to 5 dL/g.
 8. A laminated material, comprising: asupport; and a liquid-crystal polymer film disposed on the support,wherein the liquid-crystal polymer film includes the liquid-crystalpolymer as claimed in claim
 1. 9. The laminated material as claimed inclaim 8, wherein the liquid-crystal polymer film has a thickness of 1micrometer to 100 micrometers.
 10. The laminated material as claimed inclaim 8, wherein the support comprises copper foil, glass, or aluminumfoil.
 11. The laminated material as claimed in claim 8, furthercomprising an adhesive layer disposed between the support and theliquid-crystal polymer film.
 12. A liquid-crystal polymer solution,comprising: 100 parts by weight of solvent; and 0.01 to 100 parts byweight of the liquid-crystal polymer as claimed in claim
 1. 13. Theliquid-crystal polymer solution as claimed in claim 12, wherein thesolvent comprises halogen-containing solvent, ether solvent, ketonesolvent, ester solvent, carbonate solvent, amine solvent, nitrilesolvent, amide solvent, nitro solvent, sulfide solvent, phosphidesolvent, paraffin, olefin, alcohol, aldehyde, aromatic hydrocarbon,terpene, hydrogenated hydrocarbon, heterocyclic compound, or acombination thereof.
 14. The liquid-crystal polymer solution as claimedin claim 12, further comprising another resin, and the other resincomprises thermoplastic resin or thermosetting resin.
 15. Theliquid-crystal polymer solution as claimed in claim 12, furthercomprising an additive, and the additive comprises inorganic filler,organic filler, anti-oxidant, UV absorber, thermal stabilizer, lightstabilizer, anti-aging agent, toughening agent, chain extender,plasticizer, crosslinking agent, additives for coating inks, or acombination thereof.
 16. A method of forming liquid-crystal polymerfilm, comprising: coating the liquid-crystal polymer solution as claimedin claim 13 onto a support; and removing the solvent to form aliquid-crystal polymer film on the support.
 17. The method as claimed inclaim 16, wherein the support comprises copper foil, glass, or aluminumfoil.
 18. The method as claimed in claim 16, further comprising removingthe support after forming the liquid-crystal polymer film on thesupport.